US2837555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of carbonate esters
Assignee: Dow Chemical Co
•
Filing: 1956-09-20
•
Granted: 1958-06-03
•
Expires: 1976-09-20
Abstract
No abstract record available.
Inventors
- 👤 John M Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:01
CPC Classifications
C; C07; C07C; C07C69/00; C07C69/96; C07C68/00; C07C68/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
53 words
A PROCESS FOR THE PREPARATION OF A CARBONATE ESTER, WHICH COMPRISES REACTING IN A LIQUID PHASE A PHENOL SELECTED FROM THE GROUP CONSISTING OF PHENOL, CRESOL, AND MIXTURES THEREOF WITH PHOSGENE IN THE PRESENCE OF A TETRAMETHYL AMMONIUM HALIDE OF A HALOGEN HAVING AN ATOMIC NUMBER IN THE RANGE OF 17 TO 54.
Claim 2
Dependent Claim
53 words
A PROCESS FOR THE PREPARATION OF A CARBONATE ESTER, WHICH COMPRISES REACTING IN A LIQUID PHASE A PHENOL SELECTED FROM THE GROUP CONSISTING OF PHENOL, CRESOL, AND MIXTURES THEREOF WITH PHOSGENE IN THE PRESENCE OF A TETRAMETHYL AMMONIUM HALIDE OF A HALOGEN HAVING AN ATOMIC NUMBER IN THE RANGE OF 17 TO 54.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-02 | 1961-12-02 | 1962-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-02 | 1965-12-02 | 1966-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-02 | 1969-12-02 | 1970-06-03 | $7700.00 | Window Closed / Lapsed |